It is known that repeated overcharging of batteries powering portable electronic apparatuses including notebook personal computers degrades performance of the batteries. For example, the capacity of a battery at a fully charged state may drop, or the life expectancy of the battery may be shortened. In one of the related art methods to control performance degradation of the battery, an upper limit of charged level is restricted to a specific level lower than the battery capacity at the fully charged state (for example, to 80% of the battery capacity). One available information processing apparatus gradually lowers the upper limit of the charged amount of the battery with time.
Japanese Laid-open Patent Publication No. 2005-182626 discusses such a technique.
If the upper limit to the charged amount to the battery is restricted, an operation time to power an electronic apparatus is shorter than if charging is performed to a maximum chargeable capacity (rated value). This inconveniences the user of the electronic apparatus.